Fixed cutter bits, such as PDC drill bits, are commonly used in the oil and gas industry to drill well bores. One example of a conventional drilling system for drilling boreholes in subsurface earth formations is shown in FIG. 1. This drilling system includes a drilling rig 10 used to turn a drill string 12 which extends downward into a well bore 14. Connected to the end of the drill string 12 is a fixed cutter drill bit 20.
As shown in FIG. 2, a fixed cutter drill bit 20 typically includes a bit body 22 having an externally threaded connection at one end 24, and a plurality of blades 26 extending, from the other end of bit body 22 and forming the cutting surface of the bit 20. A plurality of cutters 28 are attached to each of the blades 26 and extend from the blades to cut through earth formations when the bit 20 is rotated during drilling. The cutters 28 deform the earth formation by scraping and shearing. The cutters 28 may be tungsten carbide inserts, polycrystalline diamond compacts, milled steel teeth, or any other cutting elements of materials hard and strong enough to deform or cut through the formation. Hardfacing (not shown) may also be applied to the cutters 28 and other portions of the bit 20 to reduce wear on the bit 20 and to increase the life of the bit 20 as the bit 20 cuts through earth formations.
Significant expense is involved in the design and manufacture of drill bits and in the drilling of well bores. Having accurate models for predicting and analyzing drilling characteristics of bits can greatly reduce the cost associated with manufacturing drill bits and designing drilling operations because these models can be used to more accurately predict the performance of bits prior to their manufacture and/or use for a particular drilling application. For these reasons, models have been developed and employed for the analysis and design of fixed cutter drill bits.